<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body>
    c.html
    <iframe name="fa" src="a.html" frameborder="0"></iframe>
    <iframe name="fb" src="b.html" frameborder="0"></iframe>
</body>
</html>